Method and apparatus for detecting an undesired condition of a shuttle-carried weft yarn

ABSTRACT

Running out of the weft yarn of a bobbin carried by a shuttle, or breakage of the weft yarn, are sensed independently, and upon sensing of such a condition, the respective sensing means moves to a control position. In at least one end position of the shuttle, an actuated sensing means in the control position engages in the beat-up position of the slay, stationary contact means or switch means for closing a control circuit so that a control impulse for stopping the loom is produced.

United States Patent 72] Inventor Jakob Muller 5262 Frick, Aargau,Switzerland 211 App]. No. 793,617 [22] Filed Jan. 23, 1969 [45] PatentedMay 25, 1971 [32] Priority Jan. 24, 1968 [33] Switzerland 31 1106/68[54] METHOD AND APPARATUS FOR DETECTING AN UNDESIRED CONDITION OF ASHUTTLE- CARRIED WEFI YARN 8 Claims, 3 Drawing Figs.

[52] 11.8. CI 139/371, 1 139/273 [51] Int. Cl 1103(151734,

D03d 45/ 1 0 [50] Field ofSearch 7 139/371, 370, 273, 275, 205

[56] References Cited UNITED STATES PATENTS 2,356,458 8/1944 Holmes139/371 2,456,021 12/1948 Pruitt 139/370 2,565,043 8/1951 Pruitt 7139/371 2,650,624 9/ 1953 Waterhouse 139/371 2,650,625 9/1953 Johnson139/371 2,661,028 12/1953 Siegel 139/371 2,984,265 5/1961 Dupre 139/371FOREIGN PATENTS 465,529 12/1968 Switzerland 139/371 1,511,039 '12/1967France 139/371 Primary EXaminer-James Kee Chi Attarney-Michael S.Striker ADSTRACT: Running out of the weft yarn of a bobbin carriedPatented May 25, 1971 3,580,294

2 Sheets-Sheet 2 0 I INVENTOR 4K0 3 Mum Omaha/15 kb,

ATTORNEY METHOD AND APPARATUS FOR DETECTING AN UNDESIRED CONDITION OF ASHUTTLE-CARRIED WEFT YARN BACKGROUND OF THE INVENTION In the weaving offabrics, and particularly in the weaving of narrow fabrics, such asribbons or bands, the detecting of running out of the weft yarn of theshuttle bobbin, in addition to the detection of weft yarn breakage, hasbecome of great importance since the speed of the picked shuttle is veryhigh in modern looms so that a visual observation by the operator of theloom is no longer practical.

Mechanical, photoelectrical, and electromechanical devices, includingelectronic devices and pneumatic or. hydraulic means, are known, and inparticularly one apparatus of the prior art, an electric control circuitis provided which includes two contacts in the race of the shuttle whichcooperate with two contact springs provided on the shuttle. One of thecontact springs is connected with a metal ring, and when a tensionedweft yarn tensions the spring, the yarn guide does not make contact withthe metal ring, and a control circult is interrupted. When the weft yarnbreaks, or the shuttle bobbin runs out, the yarn guide is pulled back bythe spring, makes contact with the metal ring, and closes in one endposition of the shuttle, a control circuit including a relay by whichthe loom is stopped.

This prior art construction has disadvantages, particularly that theloom is stopped only when the shuttle bobbin is completely empty, sothat the weft yarn is already without tension, and causes a fault in thewoven material. Another disadvantage of the prior art construction isthe undesired stopping of the loom by a contact between the yarn guidewith the metal ring occuring due to the vibrations of the tensionspring, without breakage of the weft yarn, or running out of the shuttlebobbin. It was also found that the contact springs are subject tofatigue so that reliable electric contact in the end position of theshuttle is not obtained.

SUMMARY OF THE INVENTION It is one object of the invention to overcomethese disadvantages of the prior art, and to obtain a stopping of theloom before the weft yarn has completely run out from the shuttlebobbin.

Another object of the invention is to stop the loom not only when theweft yarn begins to run out from the bobbin shuttle, but also when theweft yam breaks.

Another object of the invention is to stop the loom when the weft yarnbreaks or when the weft yarn begins to run out from the shuttle bydetecting either undesirable condition by two independent sensing meanswhich independently effect the stopping of the loom in at least one endposition of the shuttle.

Another object of the invention is to produce a control impulse forstopping the loom by actuating stationary control means in the beat-upposition of the slay.

With these objects in view, the stopping of the loom is produced inaccordance with the invention in the beat-up position of the slay whilethe shuttle is in an end position.

One method of the invention for detecting an undesired condition of ashuttle-carried weft yarn comprises the steps of picking the shuttlewith the weft yarn, sensing the condition of the weft yarn during thepick of the shuttle, and producing a control impulse for stopping theloom in an end position of the picked shuttle in the beat-up position ofthe slay of the loom if an undesired condition is sensed. The controlimpulse is preferably obtained by moving the shuttle by the slay at theend of the beat-up motion to a position engaging a stationary controlmeans for producing a control impulse for stopping the loom.

In accordance with the invention, the end of the weft yarn is sensed inthe shuttle, and the breakage of the weft yarn is independently sensed.

An apparatus in accordance with one embodiment of the inventioncomprises stationary supporting means on which a slay is mounted forreciprocating movement to and from a beat-up position; a shuttle mountedin a shuttle race of the slay for weft inserting movement between twoend positions; sensing means in the shuttle for sensing the weft yarnand assuming a control condition when sensing an undesired condition ofthe weft yarn; and control means supported by the stationary supportmeans in a position located opposite the shuttle in at least one of theend positions of the same, and being actuated by the sensing means onlyif the sensing means are in the control condition. The actuated controlmeans produce a control impulse for stopping the loom.

In the preferred embodiment of the invention, the shuttle has aconductive bobbin for the weft yarn and the sensing means include acircuit comprising a conductive resilient sensor contact engaging thepackage of the weft yarn on the bobbin and making contact with theconductive bobbin when the weft yarn has almost run out. Shuttle contactmeans are connected in 'series with the sensor contact and engagecorresponding contact means of the circuit of the stationary controlmeans in the beat-up position of the slay so that the control circuit isclosed and produces a control impulse for stopping the loom.

The sensing means also include a guide eye through which the weft threadpasses, and which is mounted on the shuttle for movement with theshuttle, and for dropping movement relative to the same to a controlposition. The tensioned weft yarn holds the guide eye in a normalposition, but when the weft breaks, the guide eye drops to a controlposition in which it engages a stationary switch means when the shuttleis in the end position, and the slay moves to the end of the beat-upmotion. The actuated switch means closes the control circuit of the stopcontrol means of the loom. The guide eye and the contact means of theshuttle are provided in the region of the shuttle nose.

While electric circuits and contacts are used in the preferredembodiment of the invention, mechanical, electronic, pneumatic, orhydraulic control means may be used instead of the preferredelectromechanical means of the invention. Irrespective of the preferredconstruction, the present invention provides two independent systems fordetecting the running out of the weft yarn and the breaking of the same.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary plan viewillustrating a shuttle in a position cooperating with a stationary stopcontrol means in the beat-up position of the slay;

FIG. 2 is a side elevation, partially in section along the line 2-2 inFIG. 1; and

FIG. 3 is a vertical sectional view of a part of the loom, and includingan illustration corresponding to FIG. 2, but showing the condition aftera yarn breakage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A shuttle 1 is guided in ashuttle race 21a forming a guide way in a part 21 of a reciprocable slay2 which also carries a reed 23 rearwardly of a part 21. Slay 2 ismovable between the beat-up position shown in solid lines in FIG. 3 inwhich the reed 23 beats a weft yarn into the fell 30 of the fabric 31,and a retracted position 2 shown in chain lines. The warps are operatedby heddle frames 24 to form warp sheds through which the shuttle 1is-picked before slay 2 arrives in the beatup position shown in solidlines in FIG. 3. When slay 2 is in the beat-up position, shuttle l is inthe end position shown in FIG.

1 located opposite a stationary control means 12, as best seen in FIG.1, which is mounted on a rod 13 secured to the breast beam 20 or otherbeam of the stationary supporting means of the loom. Control means 12includes control circuits by which the stop motion of the loom isoperated.

Shuttle contact means in the form of two contacts 5 and 6 are secured tothe shuttle nose 4, and engage control contacts 14 and 15 of controlmeans 12 only in the end position of shuttle 1 and in the beat-upposition of slay 2. During the pick of the shuttle 1, and while slay 2has moved out of the beat-up position shown in solid lines in FIG. 3, noengagement between shuttle contacts 5, 6 and control contacts 14 and 15is possible.

Shuttle contact 5 is connected by a conductor 7 to a resilient sensor 9which engages a package of the weft yarn 18 wound on a bobbin or quill 3which is mounted on a pin 3a for rotation in the hollow shuttle 1. Theother shuttle contact 6 is connected by conductor 8 with the bearing 10of the pin 30, and since all parts are made of conductive metal, acircuit is established if the sensor 9 engages the conductive bobbin 3in the event that the yarn package formed by weft yarn 18 on bobbin 3has almost run out. During normal operation, the sensor 9 abuts the weftyarn package on bobbin 3 so that the circuit between shuttle contacts 5and 6 is interrupted. In this normal condition, sensor 9 performs theadditional function of braking rotation of bobbin 3 due to inertia.

As long as there is a sufficiently great length of weft yarn 18 wound ina package on bobbin 3, the package holds the resilient sensor 9 spacedand insulated from the metal bobbin 3. When only the end of the weftyarn remains on bobbin 3, sensor 9 makes contact with metal bobbin 3,and an electric current impulse from a voltage source V can flow throughthe control circuit in control means 12, shuttle contact 5, conductor 7,metal sensor 9, meta] bobbin 3, bearing 10, conductor 8, shuttle contact6, and control contact while the shuttle l is in the end positionillustrated in FIG. 1, and slay 2 is in the beat-up position shown inFIG. 3 so that contacts 5, 6 and 14, and 15 engage each other. Theelectric impulse flowing through the control circuit of control means 12energizes a relay, not shown, to cause stopping of the loom andswitching off of the motor driving the same in a conventional mannerwhich is not an object of the invention.

The sensor 9 will make contact with bobbin 3 when the end portion ofweft yarn 18 is still wound in a helical winding on bobbin 3 so that thecontrol impulse for stopping the loom is given while the end portion ofthe weft yarn is still on bobbin 3. In this manner, the loom is stoppedbefore the weft thread has run out from bobbin or quill 3, which wouldhave caused a fault in the woven fabric 31.

In addition to this system for detecting the running out of the weftyarn from the bobbin, another system for detecting weft yarn breakage isprovided. Rearward of the shuttle nose 4, and in the interior of theshuttle l, a U-shaped mounting member 17 is provided in which a guideeye 11 is mounted. Mounting member 17 has two lateral downwardlyprojecting lugs 19 curved towards each other and permit a dropping ofguide eye 11 from the normal position shown in FIG. 2 to the controlposition shown in FIG. 3.

The weft yarn 18 is guided from the package on bobbin 3 to and through ayarn guide 25, from there through an eye 26 of a spring 27, another eye28 of a spring 29, from there through the guide eye 11, and to the warpshed in the region of the fell 30 of the band-shaped fabric 31.

The weft yarn portion passing through guide eye 11 is tensioned duringthe insertion into the warp shed, so that the light guide eye 11 is heldin the normal higher position shown in FIG. 2.

When the weft yarn breaks, guide eye 17 drops in mounting member 11 to alower control position shown in FIG. 3 where it is retained by the lugs19. The breaking of the weft yarn, and the dropping of the guide eye 1 1may occur during the pick of the shuttle in which event the movement ofthe shuttle to the end position shown in FIG. 1 is completed while theslay 2 moves with shuttle l to the beat-up position shown in FIGS. 1 and3.

The control means 12 includes a switch means having an actuator 16 whichcooperates with guide eye 11. Guide eye 11 arrives in a positionopposite actuator 16 before slay 2 has completed its beat-up motion. lfguide eye 11 is in the normal higher position as shown in FIG. 2,corresponding to an uninterrupted weft yarn supply, the final movementof the slay with shuttle 1 to the beat-up position will cause movementof guide eye 11 above the end of the actuator 16 so that the switchmeans in control means 12 is not operated by actuator 16.

However, if due to a weft yarn breakage, the guide eye 11 has dropped toa lower position shown in FIG. 3, it is located aligned with actuatorarm 16 while slay 2 still moves towards the beat-up position, so thatthe dropped guide eye 11 in the control position shown in FIG. 3,couples the slay and the shuttle with the actuator 16 whereby the sameis pushed to the right as viewed in the drawing until the slay arrivesin the beatup position shown in FIG. 3 so that the switch means operatedby the actuator 16 completes a control circuit in control means 12 andcauses stopping of the loom. It will be understood that instead of aswitch means provided with actuator 16, a microswitch can be providedand actuated by the dropped guide eye 11.

The guide eye 11 is not only capable of detecting weft breakage, butwill drop to the control position of FIG. 3 if the weft yarn becomesslack for any reason. For example, if the weft yarn runs out from bobbin3 completely, guide eye 1 1 will drop, and the loom will be stopped inthe beat-up position of the slay.

The mounting of the guide eye 11 as shown in the drawing may bemodified, and any other weft yarn guide capable of dropping to a controlposition when the weft yarn breaks, may be used. It is also possible toprovide an arrangement in which the dropped guide eye effects closing ofa circuit through the cooperating shuttle contact 5, 6 and controlcontacts 14 and 15 for stopping the loom. Also, the sensing circuitbetween shuttle contact 5, 6 may be differently connected. Instead of anelectric switch operated by actuator 16, a pneumatic or hydraulic valvecould be operated by actuator 16 to stop the loom by a pneumatic orhydraulic servomotor.

It will be understood that first sensing means 5 to 10 have a controlposition in which sensor 9 makes contact with bobbin 3, and that in thiscontrol position, control means 12 produces a control impulse forstopping the loom when the slay 2 arrives in the beat-up position.

The second sensing means 11, 26 to 29, assume upon weft yarn breakage orslackening, a control position in which weft guide 11 is dropped foractuating control means 12 in the beat-up position of slay 2.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofapparatus for detecting an undesirable condition of a weft yarndiffering from the types described above.

While the invention has been illustrated and described as embodied in amethod and apparatus for detecting running out of a weft yarn from ashuttle bobbin, and breaking or slackening of the weft yarn by sensingmeans and control means producing a control impulse in the beat-upposition of the slay of the loom, it is not intended to be limited tothe details shown, since various modifications and structural changesmay be made without departing in any way from the spirit of the presentinvention.

What I claim as new and desired to be protected by Letters Patent is setforth in the appended claims.

1. The method of detecting in a loom an undersired condition of a weftyarn wound on a quill of a shuttle, comprising the steps of picking theshuttle with the would up weft yarn; sensing during the picking the weftyarn on the quill and also a quill portion uncovered by the unwound weftyarn; independently sensing during picking the tension of the weft yam,and

producing a control impulse only in an end position of the. pickedshuttle and in the beat-up position of the slay of the loom when anuncovered portion of said quill is sensed during the pick, and also whenlow tension and slackness of the weft yarn is sensed during the samepick so that the loom is stopped after the pick when either running outof the weft yarn on the quill of the shuttle, or breakage of the weftyarn is sensed during the pick.

2. The method of claim 1 wherein the step of producing said controlimpulse includes moving the shuttle by the slay at the end of thebeat-up motion to a position engaging a stationary control means forproducing a control impulse for stopping the loom.

3. Apparatus for detecting in a loom an undersired condition of ashuttle-carried weft yarn, comprising stationary support means; a slaymounted on said supporting means for reciprocating movement to and froma beat-up position, and having a shuttle race; a shuttle mounted in saidshuttle race for weft-inserting picks between two end positions, andhaving a quill on which a package of the weft yarn is wound; firstsensing means on said shuttle for sensing the yarn wound on said quilland moving to a first control position when sensing a portion of thequill uncovered by the unwound weft yarn; second sensing means on saidshuttle for sensing the tension of a portion of said weft yarn andmoving to a second control position when said weft yarn is slack orbreaks; and control means supported by said stationary supporting meansin a position located opposite said shuttle in at least one of said endpositions of the same and being actuated by said first and secondsensing means in said first and second control positions, respectively,when said slay has moved with said shuttle and first and second sensingmeans to said beat-up positions, said actuated control means producing acontrol impulse for stopping the loom.

4. Apparatus as claimed in claim 3 wherein said control means include afirst stop control device engaged and actuated by said first sensingmeans in said first control position, and a second stop control deviceengaged and actuated by said second sensing means in said second controlposition when said slay is in said beat-up position.

5. Apparatus as claimed in claim 3 wherein said guide includesconductive material; wherein said first sensing means includes a circuitcomprising a conductive resilient sensor contact engaging the package ofthe weft yarn on said quill and making contact with said conductivequill in said first control position, and shuttle contact meansconnected in series with said sensor contact; and wherein said controlmeans comprises contact means engaged by said shuttle contact means insaid beat-up position.

6. Apparatus as claimed in claim 3 wherein said second sensing meansinclude a guide eye through which said weft yarn passes; wherein saidshuttle includes mounting means mounting said guide eye for movementwith said shuttle, and for dropping movement relative to the same tosaid second control position; comprising means for tensioning the weftyarn wherein the tensioned weft yarn holds said guide eye while a brokenweft yarn releases said guide eye so that the same drops said secondcontrol position; and wherein said control means include a switch meansengaged and actuated by said guide eye in said second control positionin said end position of said shuttle at the end of the movement of saidslay to said beat-up position.

7. Apparatus as claimed in claim 3; wherein said guide includesconductive material; wherein said first sensing means includes a circuitcomprising a conductive resilient sensor contact engaging the package ofthe weft yarn on said quill and making contact with said conductivequill in said first control position, and shuttle contact meansconnected in series with said sensor contact; wherein said secondsensing means include a guide eye through which said weft thread passes;wherein said shuttle includes mounting means mounting said guide eye formovement with said shuttle, and for dropping movement relative to thesame to said second control position; comprising means for tensioningthe weft yarn; wherein the tensioned weft yarn holds said uide eye whilea broken weft yarn releases said guide eye so at the same drops saidsecond control position; and wherein said control means include a switchmeans engaged and actuated by said guide eye in said second controlposition in said end position of said shuttle at the end of the movementof said slay to said beat-up position, and a stop control circuit havingcontact means engaged by said shuttle contact means in said beat-upposition of said slay.

8. Apparatus as claimed in claim 7 wherein said contact means of saidshuttle and of said stop control circuit each include two contacts.

1. The method of detecting in a loom an undersired condition of a weftyarn wound on a quill of a shuttle, comprising the steps of picking theshuttle with the would up weft yarn; sensing during the picking the weftyarn on the quill and also a quill portion uncovered by the unwound weftyarn; independently sensing during picking the tension of the weft yarn;and producing a control impulse only in an end position of the pickedshuttle and in the beat-up position of the slay of the loom when anuncovered portion of said quill is sensed during the pick, and also whenlow tension and slackness of the weft yarn is sensed during the samepick so that the loom is stopped after the pick when either running outof the weft yarn on the quill of the shuttle, or breakage of the weftyarn is sensed during the pick.
 2. The method of claim 1 wherein thestep of producing said control impulse includes moving the shuttle bythe slay at the end of the beat-up motion to a position engaging astationary control means for producing a control impulse for stoppingthe loom.
 3. Apparatus for detecting in a loom an undersired conditionof a shuttle-carried weft yarn, comprising stationary support means; aslay mounted on said supporting means for reciprocating movement to andfrom a beat-up position, and having a shuttle race; a shuttle mounted insaid shuttle race for weft-inserting picks between two end positions,and having a quill on which a package of the weft yarn is wound; firstsensing means on said shuttle for sensing the yarn wound on said quilland moving to a first control position when sensing a portion of thequill uncovered by the unwound weft yarn; second sensing means on saidshuttle for sensing the tension of a portion of said weft yarn andmoving to a second control position when said weft yarn is slack orbreaks; and control means supported by said stationary supporting meansin a position located opposite said shuttle in at least one of said endpositions of the same and being actuated by said first and secondsensing means in said first and second control positions, respectively,when said slay has moved with said shuttle and first and second sensingmeans to said beat-up positions, said actuated control means producing acontrol impulse for stopping the loom.
 4. Apparatus as claimed in claim3 wherein said control means include a first stop control device engagedand actuated by said first sensing means in said first control position,and a second stop control device engaged and actuated by said secondsensing means in said second control position when said slay is in saidbeat-up position.
 5. Apparatus as claimed in claim 3 wherein said guideincludes conductive material; wherein said first sensing means includesa circuit comprising a conductive resilient sensor contact engaging thepackage of the weft yarn on said quill and making contact with saidconductive quill in said first control position, and shuttle contactmeans connected in series with said sensor contact; and wherein saidcontrol means comprises contact means engaged by said shuttle contactmeans in saId beat-up position.
 6. Apparatus as claimed in claim 3wherein said second sensing means include a guide eye through which saidweft yarn passes; wherein said shuttle includes mounting means mountingsaid guide eye for movement with said shuttle, and for dropping movementrelative to the same to said second control position; comprising meansfor tensioning the weft yarn wherein the tensioned weft yarn holds saidguide eye while a broken weft yarn releases said guide eye so that thesame drops said second control position; and wherein said control meansinclude a switch means engaged and actuated by said guide eye in saidsecond control position in said end position of said shuttle at the endof the movement of said slay to said beat-up position.
 7. Apparatus asclaimed in claim 3; wherein said guide includes conductive material;wherein said first sensing means includes a circuit comprising aconductive resilient sensor contact engaging the package of the weftyarn on said quill and making contact with said conductive quill in saidfirst control position, and shuttle contact means connected in serieswith said sensor contact; wherein said second sensing means include aguide eye through which said weft thread passes; wherein said shuttleincludes mounting means mounting said guide eye for movement with saidshuttle, and for dropping movement relative to the same to said secondcontrol position; comprising means for tensioning the weft yarn; whereinthe tensioned weft yarn holds said guide eye while a broken weft yarnreleases said guide eye so that the same drops said second controlposition; and wherein said control means include a switch means engagedand actuated by said guide eye in said second control position in saidend position of said shuttle at the end of the movement of said slay tosaid beat-up position, and a stop control circuit having contact meansengaged by said shuttle contact means in said beat-up position of saidslay.
 8. Apparatus as claimed in claim 7 wherein said contact means ofsaid shuttle and of said stop control circuit each include two contacts.